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GSE26366
Homo sapiens
199 Downloadable Samples
Affymetrix Human Genome U133A Array (hgu133a)
Description
Notch signaling plays both oncogenic and tumor suppressor roles, depending on cell type. In contrast to T cell acute lymphoblastic leukemia (T-ALL), where Notch activation promotes leukemogenesis, induction of Notch signaling in B-ALL leads to growth arrest and apoptosis. The Notch target Hairy/Enhancer of Split1 (HES1) is sufficient to reproduce this tumor suppressor phenotype in B-ALL, however the mechanism is not yet known. Here we report that HES1 regulates pro-apoptotic signals via the novel interacting protein Poly ADP-Ribose Polymerase1 (PARP1) in a cell type-specific manner. The interaction of HES1 with PARP1 inhibits HES1 function, induces PARP1 activation and results in PARP1 cleavage in B-ALL. HES1-induced PARP1 activation leads to self-ADP ribosylation of PARP1, consumption of NAD+, diminished ATP levels, and translocation of the Apoptosis Inducing Factor (AIF) from mitochondria to the nucleus, resulting in apoptosis in B-ALL, but not T-ALL. Importantly, induction of Notch signaling via the Notch agonist peptide DSL can reproduce these events and leads to BALL apoptosis. The novel interaction of HES1 and PARP1 in B-ALL modulates the function of the HES1 transcriptional complex and signals through PARP1 to induce apoptosis. This mechanism reveals a cell type-specific pro-apoptotic pathway which may lead to Notch agonist-based cancer therapeutics.
Publication Title
Notch/HES1-mediated PARP1 activation: a cell type-specific mechanism for tumor suppression.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 140 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
Acute lymphoblastic leukemia (ALL), the commonest childhood malignancy, is characterized by recurring gross and submicroscopic structural genetic alterations that contribute to leukemogenesis. Disordered epigenetic regulation is a hallmark of many tumors, and while analysis of DNA methylation of limited numbers of genes or ALL samples suggests epigenetic alterations may also be important, a large-scale integrative genome-wide analysis evaluating DNA methylation in ALL has not been performed. Here, we report an integrated epigenomic, transcriptional and genetic analysis of 167 childhood ALL cases, comprising B-progenitor ALL with hyperdiploidy (N=26), ETV6-RUNX1 (N=27), TCF3-PBX1 (N=9), BCR-ABL1 (N=19), rearrangement of MLL (MLLr) (N=20), rearrangement of CRLF2 (N=11, CRLF2r), deletion of ERG (N=11), miscellaneous or normal karyotype (N=14), and T-lineage ALL (N=30), including 4 MLLr cases and 7 cases with early T-cell precursor immunophenotype. Genome-wide profiling of structural DNA alterations was performed for all cases using Affymetrix 500K and SNP 6.0 arrays. Affymetrix U133A gene expression profiling data was available for 154 cases. Genome-wide methylation profiling was performed using the HELP microarray assay, which measures methylation at approximately 50,000 CpGs distributed among 22,722 Refseq promoters. Methylation data was compared to that of normal pro-B (CD34+CD19+sIg-), pre-B (CD34-CD19+sIg-) and mature B (CD34-CD19+sIg+) cells FACS-sorted from bone marrow of 6 healthy individuals. Unsupervised hierarchical clustering of the top 4043 most variable methylation probesets identified 9 B-ALL clusters with significant correlation to specific genetic lesions including ETV6-RUNX1, MLLr, BCR-ABL1, CRLF2r, TCF3-PBX1 and ERG deletion. T-ALLs and hyperdiploid B-ALLs also defined specific DNA methylation clusters. Supervised analysis including limma and ANOVA identified distinct DNA methylation signatures for each subtype. Notably, the strength of these signatures was subtype dependent, with more differentially methylated genes observed in ALL cases with genetic alterations targeting transcriptional regulators (e.g. ETV6-RUNX1 and MLLr) and fewer genes in cases with alterations deregulating cytokine receptor signaling (e.g. CRLF2r). Aberrant DNA methylation affected specific and distinct biological processes in the various leukemia subtypes implicating epigenetic regulation of these pathways in the pathogenesis of these different forms of ALL (e.g. TGFB and TNF in ERG deleted leukemias; telomere and centriole regulation in BCR-ABL1 ALL). Aberrantly methylated genes were also enriched for binding sites of known or suspected oncogenic transcription factors that might represent cooperative influences in establishing the phenotype of the various B-ALL subtypes. Most importantly, an integrated analysis of methylation and gene expression of these ALL subtypes demonstrated striking inversely correlated expression of the corresponding gene transcripts. The methylation signatures of each subtype exhibited only partial overlap with those of normal B cells, indicating that the signatures do not simply reflect stage of lymphoid maturation. In a separate approach, we discovered that 81 genes showed consistent aberrant methylation across all ALL subtypes, including the tumor suppressor PDZD2, HOXA5, HOXA6 and MSH2. Inverse correlation with expression was confirmed in 66% of these genes. These data suggest the existence of a common epigenetic pathway underlying the malignant transformation of lymphoid precursor cells. Integrative genetic and epigenetic analysis revealed hypermethylation of genes on trisomic chromosomes that do not show increased expression, suggesting that epigenetic silencing may control genes within amplified regions and explain why only selected genes are overexpressed. Finally, analysis of individual genes targeted by recurring copy number alterations in ALL revealed a subset of genes also targeted by abnormal methylation, with corresponding changes in gene expression (e.g. ERG, GAB1), suggesting that such genes are inactivated far more frequently than suggested by genetic analyses alone. Collectively, the data support a key role of epigenetic gene regulation in the pathogenesis of ALL, and point towards a scenario where genetic and epigenetic lesions cooperatively determine disease phenotype.
Publication Title
Integrated genetic and epigenetic analysis of childhood acute lymphoblastic leukemia.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 10 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
The oncogenic proteins expressed in human cancer cells are exceedingly difficult targets for drug discovery due to intrinsic properties of the Ras GTPase switch. As a result, recent efforts have largely focused on inhibiting Ras-regulated kinase effector cascades, particularly the Raf/MEK/ERK and PI3 kinase/Akt/mTOR pathways. We constructed murine stem cell leukemia virus (MSCV) vectors encoding oncogenic K-RasD12 with additional second site amino acid substitutions that that impair PI3 kinase/Akt or Raf/MEK/ERK activation and performed bone marrow transduction/transplantation experiments in mice. In spite of attenuated signaling properties, defective K-Ras oncoproteins induced aggressive clonal T lineage acute lymphoblastic leukemia (T-ALL). These leukemias exhibited a high frequency of somatic Notch1 mutations, which is also true of human T-ALL. Multiple independent T-ALLs restored full oncogenic Ras activity by acquiring third site mutations within the viral KrasD12 transgenes. Other leukemias with undetectable PTEN and elevated phosphoryated Akt levels showed a similar gene expression profile to human early T progenitor (ETP) T-ALL. Expressing oncoproteins that are defective for specific functions is a general strategy for assessing requirements for tumor maintenance and uncovering potential mechanisms of drug resistance in vivo. In addition, our observation that defective Kras oncogenes regain potent cancer initiating activity strongly supports simultaneously targeting distinct components of Ras signaling networks in the substantial fraction of cancers with RAS mutations.
Publication Title
Defective K-Ras oncoproteins overcome impaired effector activation to initiate leukemia in vivo.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 16 Downloadable Samples
- Illumina HumanHT-12 V4.0 expression beadchip
Description
Analysis of lineage depleted human cord blood cells sequentially transduced with retro- (BCR-ABL1) and lentiviral (Ik6) vectors and the corresponding controls. Results provide important informations on the collaboration of BCR-ABL1 and Ik6 in human hematopoietic cells.
Publication Title
Dominant-negative Ikaros cooperates with BCR-ABL1 to induce human acute myeloid leukemia in xenografts.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 12 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
TCF-1 is an HMG family transcription factor which is known to be critical for T cell development. We discovered that it has a unique role in suppressing malignant transformation of developing thymocytes at early stages. We identified ID2 and LEF-1 as key TCF-1 target genens in tumor suppression.
Publication Title
The TCF-1 and LEF-1 transcription factors have cooperative and opposing roles in T cell development and malignancy.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 55 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
Despite improved therapy, approximately one-fifth of children with acute T-lymphoblastic leukemia (T-ALL) succumb to the disease, suggesting unrecognized biologic heterogeneity that may contribute to drug resistance. We studied leukemic cells, collected at diagnosis, to identify features that could define this high-risk subgroup. A total of 139 patients with T-ALL were treated consecutively from 1992 to 2006 at this institution. Their leukemic cells were examined with multiparameter flow cytometry, single nucleotide polymorphism arrays and other methods of genomic analysis. Survival rates and probabilities of treatment failure were calculated for subgroups considered to have biologically distinct forms of T-ALL.
Publication Title
Early T-cell precursor leukaemia: a subtype of very high-risk acute lymphoblastic leukaemia.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 14 Downloadable Samples
IlluminaHiSeq2000
Description
T-cell acute lymphoblastic leukemia (T-ALL) is an immature hematopoietic malignancy driven mainly by oncogenic activation of NOTCH1 signaling. In this study we abrogated the expression of JMJD3 (KDM6B) and UTX (KDM6A) H3K27me3 demethylases in human T-ALL lines and assayed for genome-wide expression changes using RNA sequencing. This piece of data was further integrated to ChIP-Sequencing analysis of H3K27me3 from the same treatment as well as H3K27me3 and JMJD3 genome-wide analysis from treatment of T-ALL lines with the GSKJ4 inhibitor. These results, coupled to genomic analysis of primary samples for the genomic status of the UTX gene in T-ALL, helped us to identify a hitherto unknown role of JMJD3as an oncogenice facilitator in leukemia whereas UTX seems to play a tumor suppressor role. Overall design: Whole RNA was extracted from 1-5 million T-ALL (lines) cells or primary cells using the RNAeasy kit (Qiagen) according to the manufacturer’s protocol. Poly-A+ (magnetic oligodT-containing beads (Invitrogen)) or Ribominus RNA was used for library preparation. cDNA preparation and strand-specific library construction was performed using the dUTP method. Libraries were sequenced on the Illumina HiSeq 2000 using 50bp single-read method. Differential gene expression analysis was performed for each matched knockdown vs control pairs, separately in each biological or technical replicate in each of two cell lines (CUTLL1, CEM). Three types of comparisons were tested: (a) JMJD3 knockdown vs Renilla, (b) JMJD3 knockdown vs UTX knockdown, and (c) UTX knockdown vs Renilla. Analysis was performed using both DEGseq and Cufflinks packages leading to very similar conclusions.
Publication Title
Contrasting roles of histone 3 lysine 27 demethylases in acute lymphoblastic leukaemia.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 12 Downloadable Samples
- IlluminaHiSeq2000
Description
T-cell acute lymphoblastic leukemia (T-ALL) is an immature hematopoietic malignancy driven mainly by oncogenic activation of NOTCH1 signaling. In this study we chemically inhibited the H3K27me3 demethylase JMJD3 using the GSKJ4 inhibitor and assayed for genome-wide changes in H3K27me3 and JMJD3 enrichment. This piece of data was further integrated to expression changes using RNA sequencing as well as ChIP-Sequencing analysis of H3K27me3 upon genomic knock-down of JMJD3 and UTX. These results, coupled to genomic analysis of primary samples for the genomic status of the UTX gene in T-ALL, helped us to identify a hitherto unknown role of JMJD3 as an oncogenice facilitator in leukemia whereas UTX seems to play a tumor suppressor role. Overall design: Whole RNA was extracted from 1-5 million primary cells from CUTLL1 human T cell leukemia cells untreated or treated with 2micromolar GSKJ4 using the RNAeasy kit (Qiagen) according to the manufacturer’s protocol. Poly-A+ (magnetic oligodT-containing beads (Invitrogen)) or Ribominus RNA was used for library preparation. cDNA preparation and strand-specific library construction was performed using the dUTP method. Libraries were sequenced on the Illumina HiSeq 2000 using 50bp single-read method. Differential gene expression analysis was performed between knockout vs wild-type background samples. Analysis was performed using DEGseq package leading to very similar conclusions.
Publication Title
Contrasting roles of histone 3 lysine 27 demethylases in acute lymphoblastic leukaemia.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 11 Downloadable Samples
- Illumina HiSeq 2000
Description
T-cell acute lymphoblastic leukemia (T-ALL) is an immature hematopoietic malignancy driven mainly by oncogenic activation of NOTCH1 signaling. In this study we conduct expression analysis in NOTCH1-IC-induced tumors in Utx wild-type (Utx+/+ or Utx+/Y) and knockout (Utx-/Y) background. These results, coupled to genomic analysis of primary samples for the genomic status of the UTX gene in T-ALL, helped us to characterize the hitherto understudied role of Utx as an oncogenic facilitator in leukemia and the contrasting expression signatures between JMJD3 and UTX in this disease. Overall design: Whole RNA was extracted from 1-5 million primary cells from Notch1-IC-expressing (sorted populations of) mouse T-ALL tumors using the RNAeasy kit (Qiagen) according to the manufacturer’s protocol. Poly-A+ (magnetic oligodT-containing beads (Invitrogen)) or Ribominus RNA was used for library preparation. cDNA preparation and strand-specific library construction was performed using the dUTP method. Libraries were sequenced on the Illumina HiSeq 2000 using 50bp single-read method. Differential gene expression analysis was performed between knockout vs wild-type background samples. Analysis was performed using DEGseq package leading to very similar conclusions.
Publication Title
Contrasting roles of histone 3 lysine 27 demethylases in acute lymphoblastic leukaemia.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 3 Downloadable Samples
- Illumina HiSeq 2000
Description
Triplicate RNA-seq expression analysis of bone marrow pre-B cells isolated from mice, to demonstrate repertoire at the IgH locus Overall design: Triplicate RNA-seq expression analysis of bone marrow pre-B cells
Publication Title
Pax5 loss imposes a reversible differentiation block in B-progenitor acute lymphoblastic leukemia.
Sample Metadata Fields
No sample metadata fields
View Samples